Introduction: Big Draws
First we have to define what constitutes a big draw. While there is no one standard definition, for the purposes of this discussion we will define a big draw as one that has more than 9 outs to improve against Top Pair. It's not a perfect definition as a) sometimes we aren't up against Top Pair but rather a stronger hand against which we have fewer outs b) sometimes (but infrequently) we improve to the second best hand. But overall I feel this is a good starting definition to distinguish these draws from smaller, garden-variety 8- and 9- out draws like OESD and small Flush Draws.
Examples of Big Draws:
1. Nut Flush Draw: A

9

on a J

7

2

flop. This draw has 12 outs to improve against all Top Pair and Overpair hands other than AJ and AA. Against JT-/QJ/KJ/QQ/KK we have 12 outs, and so based on our definition above the NFD just barely makes it as a Big Draw.
2. Pair + OESD: 8

8

on 6

7

9

. This draw has 10 outs against a hand like A9.
3. Pair + Flush Draw: A

9

on a J

9

2

flop. This draw has 14 outs (9 diamonds, 2 9s and 3 As) against KJ and 11 outs against AJ.
4. Flush Draw + Gutshot: A

9

on a J

8

7

. This draw has 12 out (9 diamonds and 3 non-diamond Ts vs. a hand like AJ.
5. Flush Draw + Overs: A

K

on a T

7

2

flop. This draw has anywhere between 15 outs against a hand like JT or JJ to 12 outs against a hand like AT.
6. Flush Draw + OESD or OESFD: 8

9

on a T

7

2

flop or a A

:J

on a T

9

8

flop.
Key Concepts:
1. Tension between
Implied Odds and
Fold Equity. Usually there is an inverse relationship between Implied Odds (IO) and Fold Equity (FE). The higher the Fold Equity the lower the Implied Odds and vice versa.
2. Straight draws are harder for opponents to see and therefore have higher Implied Odds. Flush draws are easier for opponents to see and therefore have lower implied odds.
3. All else equal, you should lean towards calling rather than raising with draws most of whose outs have high implied odds.
4.
Semi-bluffing requires fold equity. If your knowledge of your opponents makes you strongly believe that they will not fold any of their original range in a given situation, then semi-bluffing makes no sense.
5.
Bluffing Outs. When there are multiple draws possible on a board and you have the draw with a high Implied Odds component (e.g. Pair + OESD) you can sometimes call with the plan on value betting when one of your hard-to-see outs comes in AND also bluffing when the 'obvious' draw such as a flush draw but which you do not have comes in.
6. Position enhances the value of draws, both when bluffing and when extracting value.
7. High stack depth/High SPR increase the fold equity of big draws vs. medium-strength hands.
8. Always keep track of the strength of villain's Original Range (O-range) and their Continuing Range (C-range). The further they continue, the stronger their C-range becomes, which means Implied Odds go up and Fold Equity goes down. For example, if you raise a big draw in position after a tight opponent c-bets the flop, and he calls and then bets the turn, it is very unlikely that opponent is folding much of his range on the turn with normal stack depth, but it is quite possible that he will call off the rest of his stack on the river even when an obvious draw comes in.
9.
Big draws shrink when facing strong multi-way action, as it becomes increasingly likely that one of the opponents is holding a better draw and another a better made hands (see the last example below). This is a good time to re-evaluate and let an otherwise 'big' draw go.
Sample Equities
Pair + FD vs. a TP+ range
A

9

on a J

9

2

flop. If we think we are up against a range of TPGK+, our equity is:
Board: Jd 9s 2d
Dead:
equity win tie pots won pots tied
Hand 0: 45.036% 45.03% 00.00% 20508 1.50 { Ad9d }
Hand 1: 54.964% 54.96% 00.00% 25029 1.50 { JJ, 99, 22, AJs, KJs, QJs, J9s, AJo, KJo, QJo, J9o }
Same situation but if the range we are up against strengthens to TPTK+, our equity drops to 39%. If it's 2pr+ our equity drops to 35%.
Flush Draw + OESD: A

:J

on a T

9

8

flop. Our equity against a range that's Overpairs+ is:
Board: Td 9d 8s
Dead:
equity win tie pots won pots tied
Hand 0: 49.090% 47.51% 01.58% 34336 1141.50 { AdJd }
Hand 1: 50.910% 49.33% 01.58% 35651 1141.50 { 88+, QJs, T9s, 98s, 76s, QJo, T9o, 98o, 76o }
Against 2pr+ our equity drops slightly to 47%.
Hand Examples
1. NFD In Position
(note: I am doing this one the long-hand. I don't claim to have all the answers but wanted to put in some solid work on different lines. If you are in the 'tl;dr' camp - do us both a favor and 'dr' silently).
Villain is a solid TAG. He understands which boards are good for c-betting and capable of folding marginal hands under pressure, although he is not weak-tight and does not require the nuts to continue against raises. Effective stacks are 100bbs.
Villain opens to 4bbs in EP. We call OTB with A

Q

.
At this point we believe that villain's range is something like:
{AA-22,AKo-AJo,AKs-ATs,KQs-KJs,QJs,JTs,T9s,98s,87s,76s}
We think that 77+, AQ+ part of the range is always there, and 22-66, SCs and weaker suited Broadway is there some portion of the time depending on opponent specifics, how tough/weak he perceives the game, etc. Our pre-flop equity against that range is only ~ 38% but we believe that we can take away the pot on certain flops using position.
Flop (8.5bbs): K

7

2
Villain c-bets for 6bbs. At this point we can't narrow villain's range much as this is the board we believe based on his tendencies he will c-bet near 100% of the time. Here is how his pre-flop range, which we also believe to be his flop c-betting range, distributes on this flop:
Two-Pair+ 6%
Top Pair: 12%
2nd Pair/Middle Pair: 25%
3rd Pair: 17%
Flush Draw: 5%
Air: 35%
(source: Flopzilla)
Using Poker Stove our equity against his c-betting range is: 59%. Folding is out of the question, and it's a question of whether we call or raise.
Option A: Calling Flop
One question we should always ask is who is more likely to make a mistake on this and future streets as a result of our action.
We should also think about how our hand's equity changes on a blank turn.
Here, if we call, villain is unlikely to double-barrel turn with the air part of his range. If our draw comes in, it will be obvious to our opponent, so he will not commit his whole stack with the vast majority of his range. He might bet/fold the turn if the flush comes in for a little over half pot with TP+ and c/f with the rest of his range.
Scenario 1: Turn completes our draw (3
).
Our equity changes to almost 100%.
So his turn continuing range is: {KJs, KQs, AKs, KK+, 22-33, 77, 9d8d-JdTd}. That's 32% of the original range that c-bet the flop. Of this range, we can assume that 60% (TP and Overpair) is bet/folding and 40% (sets and flushes) is bet/calling. Our villain is making a mistake when he is betting any part of his range on this turn
against our specific hand. I do not believe that he is making a mistake against our overall flop-calling range in this situation. If our places were reversed we would probably play the turn similarly.
The above assumptions lead us to believe that when he checks the turn his range is too weak to call any reasonable bet, and he is checking to c/f rather than c/c.
Scenario 2: Turn is a blank (3
)
Our equity against his original range drops slightly from 58% to ~ 53%
Let's assume he bets the same range as in scenario 1 or {KJs, KQs, AKs, KK+, 22-33, 77, 9d8d-JdTd}. Our equity against his turn betting range drops to ~ 27%. He is unlikely to make a mistake with any part of his range if we call as he is unlikely to call off his stack if we call turn and a flush comes in on the river.
An interesting question is whether or not we can credibly take the call flop/shove blank turn line. If he folds all the TP- part of his betting range, then we can get him to make a mistake with that part of his range. Furthermore, I am not 100% sure, but I feel some players have a sizing tell here on the turn - if they intend to bet/fold turn they bet smaller, closer to 50% of pot than if they intend to bet/call.
If he checks, his range is as weak as in Scenario 1 but now he is much more likely to c/c the 2nd pair/middle pair part of his range so I don't think we can make him make a major mistake by floating flop and betting a blank turn when checked to.
Option B: Raising Flop
Instead of flatting villain's 6bb c-bet on the flop, we can raise it to say 24bbs. I think it's safe to assume that a solid TAG opponent is definitely going to fold everything except: {KJs, KQs, AKs, AA, 22, 77, KK, 9d8d-JdTd}. That means that he is folding ~ 70% of his c-betting range. We are risking 24bb to win 14.5bb and need a fold ~62% of the time if our EV is 0 if villain doesn't fold, so this means our flop raise is +EV just based on our Fold Equity.
If villain 3 bet-shoves, we can assign a range of {KK, 22, 77 and 9d8d-JdTd}. Our equity against that range is 33%. We have to call 66bb, so the EV of our call is near zero. In practice, since sets are always in the range but FDs are in the range less than 100% of the time we should probably fold.
The interesting case happens when Villain just calls. This range is the toughest to assign. Some TAGs will fold hands like KJs and KQs on the flop. Others will call with all TPs and AA and some 2nd pairs. Let's say that this TAG is not willing to fold TP on the flop here and that his flop calling range is: {AA, KJs, KQs, AK}. Our equity against that range on a blank turn is only 22%. So the question is, with the pot being 57bbs and us having 72bbs behind, do we have fold equity against his flop calling range if he checks? I think this depends on a lot of gameflow variables. In a vacuum, I honestly don't know and would err on checking behind turn at 2/5 NL and below but am open to others' thoughts.
2. Pair + FD In Position
Villain is the same TAG from Example 1 above. He opens in EP with the same range of: {AA-22,AKo-AJo,AKs-ATs,KQs-KJs,QJs,JTs,T9s,98s,87s,76s}
We flat OTB with 6

7

.
Flop (8.5bbs): K

7

2
Villain c-bets for 6bb. If we assume that he is c-betting his entire range as we did in Example 1, our equity is higher than before, or ~ 66%. On a blank turn, our equity against his original range drops, but not that much, to ~60%.
If we say the blank turn is a 3

, and we assume his turn betting range is: {KK+,77,33-22,KJs+,AdQd,AdJd,AdTd,QdJd,JdTd,Td9d,9d8d}, our equity on the turn against that range is 35%. That means that we can profitably call a less than pot-sized bet. However, we have to play the river carefully to make sure we avoid RIO if he open-shoves/pots a diamond river. In that case we might have to fold. However, if the diamond comes in, we can profitably bet 1/2 pot and expect to get looked up by a number of worse hands like sets and AA and possibly AK.
On the other hand, if we raise flop, our fold equity is similar to that in example 1 (~65%), but our equity against the range that 3-bet shoves the flop is 40% if he always shoves all draws and 36% if he only includes the NFDs in his flop 3-betting range. So with stacks set-up where he c-bets for 6bbs, we raise to 24bbs and he shoves, we are getting the odds to call.
Of the two lines, I personally like flatting better when in position, because I think there are more ways for our opponent to make a mistake on future streets than if we raise, but I think both lines are +EV.
Note: The above two examples were against a decent TAG capable of folding medium-strength hands to some pressure. Against someone who is more stationy than that, it becomes more correct to flat since our implied odds go up and fold equity goes down. Since most 2/5NL and below opponents are known for calling too much, you should seriously consider opponent tendencies and how much fold equity you really have before semi-bluffing in position. I am still tempted to semi-bluff big draws that have mostly obvious outs OOP, given the difficulty of extracting value on turn/river when we hit against all but the most stationy opponents.
Finally, here is an example of when we want to release a big draw:
3. Pair + FD facing multi-way action.
NIT opens in EP for 4bbs. We call OTB with 6

7

and a solid TAG flats in the BB. Stacks are 100bb.
Flop (12bb): K

T

7
BB leads for pot, EP NIT raises to 40bbs and its our action. Here is our equity:
Board: Kd Td 7s
Dead:
equity win tie pots won pots tied
Hand 0: 40.499% 40.29% 00.21% 84050 428.00 { TT, 77, AdQd, AdJd, Ad9d, Ad8d, Ad6d, Ad5d, Ad4d, Ad3d, Ad2d }
Hand 1: 17.827% 17.83% 00.00% 37186 0.00 { 7d6d }
Hand 2: 41.674% 41.47% 00.21% 86501 428.00 { KK+, TT, AKs, AKo }
Even though we might think we have a 'big draw', between BB's range having a lot of draws that dominate us if we do improve and the EP NIT's range being almost all made hands that, our equity against both of them combined is terrible and we have no fold equity. We should fold.
Conclusion
I tried to do my best to go over both the concepts I view as key, and give some examples with a more in-depth than usual analysis. I know this was somewhat long, and even though it's long it's by no means complete. I welcome all additions/corrections/further thoughts, as I did this part to give back to the forum and in part to force myself to do in-depth Poker Stove/Flopzilla range analysis to inform my own play at the table.